.overview {
  display: flex;
}
.overview .left .leftTop {
  display: flex;
  position: relative;
}
.overview .left .leftTop .smallPic {
  width: 500px;
  height: 500px;
  border: 1px solid #dfdfdf;
  position: relative;
  overflow: hidden;
}
.overview .left .leftTop .smallPic img{
  width: 100%;
  height: 100%;
}
.overview .left .leftTop .smallPic .mask {
  width: 250px;
  height: 250px;
  background-color: rgba(255, 255, 255, 0.5);
  border: 1px solid #ddd;
  position: absolute;
  left: 0;
  top: 0;
  display: none;
}
.overview .left .leftTop .bigPic {
  width: 500px;
  height: 500px;
  border: 1px solid #dfdfdf;
  overflow: hidden;
  position: absolute;
  left: 520px;
  top: 0;
  display: none;
  z-index: 99;
}
.overview .left .leftTop .bigPic img {
  width: 1000px;
  height: 1000px;
  position: absolute;
}
.overview .left .leftBottom {
  width: 500px;
  margin-top: 5px;
  display: flex;
}
.overview .left .leftBottom a {
  width: 10px;
  height: 54px;
  background-color: #EBEBEB;
  border: 1px solid #ccc;
  text-align: center;
  line-height: 54px;
}
.overview .left .leftBottom a:nth-child(1) {
  margin-right: 4px;
}
.overview .left .leftBottom .thumbnail {
  width: 472px;
  height: 56px;
  overflow: hidden;
  position: relative;
}
.overview .left .leftBottom .thumbnail ul {
  white-space: nowrap;
  font-size: 0;
  position: absolute;
  left: 0;
  transition: all 0.3s;
}
.overview .left .leftBottom .thumbnail ul li {
  padding: 2px;
  margin-right: 25px;
  display: inline-block;
}
.overview .left .leftBottom .thumbnail ul li img {
  border: 1px solid #ccc;
  width: 50px;
  height: 50px;
}
